Wood-bending machine



July 28,1925. y l 1,547,716

' F. H. BANCROFT A wooD'BENDING MACHINE Filed Aprilvzz. 1924 l l 2 'sheets-sheen a Patented July 2s, l19025.

UNI-TED STAT-Es FRANK H'. iaANoaoFcl,` or GARnNnn,.MAssAcHU-sTTs,.AssrGNoR To P. VDERBY `& co1.,

A .'coRroRA'rIoN oF MASSACHUSETTS. y

ING., yor" GARDNER, MASSAHUSETTS,

WOODBENDING MA'cHrNE.

Application filed April 23,1924. serial Natta-ias.' I i To all it mag/concern.'

Beit vknown that I, FRANK .BANGRoFr,

a citizen -of the United States :of America, `and resident ofGardner, in the Ycounty of orcester and State .of Massachusetts, have inventedfnew and useful Improvements in v Wood-Bending-Machines, of which the vfollowing is a specification. Y V l This invention pertains to wood bending l0 machines of the Ageneral type disclosed .in the patent to Bancroft No. 1,461,471, `dated Jfuly 10, 1.923, and moreparticularly-to improvenients .in and relating to the SO-called master-.strap y-orminga-n essential element of suchmachines.,

One objectof the presentinvention is to provide'su'ch a machine with an'improved for-m of `master-strap capablefof'withstanding the enormus strains .imposedin bending wood of unusualv thicknessbut sufficiently flexible to permit bending the wood to anyv radius likely vto be encountered in the oper- `ation of the machine; .afurther object is .to provide fory vaccurateand rapid adjust- 2 mentrof the length ofthe master-strap to accommodate pieces of wood of widely dif- Vferent length. l'

In the accompanying drawing a preferred embodiment of the inventionis illust-rated by way of example. 'f

Fig. 1 is a fragmentary transverse vertical section throughy theupper part of the the end of the bending operation;

Fig. 2 is a side elevation to larger scale showing the construction of one of the bending heads omitting certain arts and indicating Vthe means Jfor adjustably attaching the end of the master-strap thereto;

Fig. 3 is a fragmentary plan View of the head and improved master-strap; and

Fig. 4 is a transverse sect-ion on the line 4 4 of Fig. 2, omitting the master-strap.

Referring to the drawings in which a portion only of the machine is shown, the numerals 13 indicate they vertical supporting posts "upon which the top casting 14' is mounted. This top casting-preferably comprises spaced sidemembers and a trans- 50 verse member 16. The vertically movable table 17 is provided with guide openings through which the posts 13 extend, and is moved by means of rams 19l actuated by hydraulic or other pressure.

55 The table supports brackets 24 carrying pivote@ linksj fwhichgap'fllihe beading head'S. 27;, Each; bendingk head' is provided 'parallel-"guide groovesSO for support- '111g and guiding' anlulgerQS- @Olilfle'tcl by cv rod 31 to a. ,pist`o'n 32 workingin a hydraulic .cylinder33. Thebendingheads27,are con-l 'nected'ftoeach otherbyfmeans of a masterstrap V90 :of improved ,construction which `hereinafter willb'ev described -in detaih 1 Y A bracket 48;,issupportedy upon the ,trans- -yerse member 16 ofthet'opcastingi and is provided withzmeansfor attachingthe'iform c about-which thewo'od ais bent. liner v strap 39, preferably smooth vand of l flexible sheet metal, is hsupp(),I'td bythe masterstrap 90. r Tyheop'posit'e ends of the'strap 39 lare secured Vto blocksf42 which are -free to slide to alimited extentfin the channel menikbers40 which constitute abutments Vfor the yends of the respectiveV plungers 28. The

central portion of the master-strap 90 may befsupported upon an adjustable rest during the bending operation.

The above described parts are in v'general quite similar tothe vcorrespondingly numberedparts in my Patent No. 1,461,471

above referred tojwhich may be consulted yfor further informationv as to the specific construction of such parts and the general mode of .operation of the machine.

,In 'thepatented machine Athe master-strap consists of a strip of sheet Ametal but in the machine sho-Wing the parts as posltioned at present. improvedarrangement this 'masterstr'ap, designated 'generally atV 90, comprises two spaced parts and 90b (Fig. 3), con- `structed as link belts or chains. `Each belt or chain comprises series of links and 96, of the usual figure-8 shape connected pins'or rivets 97 to form a flexible chain structure. These chains, as indicated in Fig.

' 3, are of substantial width so as to distribute the pressure over the surface of the wood to be bent. n

For securing the master-strap comprising the chains to thev bending head the latteris furnished with openings 101a and 101b 1n its ends which lead to channels or Chambers extending inwardly and downwardly through llO - when, as indicated in Fig. 2, a link'is posi stantiallyequal to the thickness ofa chain link at its central or thinnest 'part so that tioned between such openings and the pins 104 and 105 are placed in the openings the link is firmly clamped and retained against withdrawl from the bending head.` A

The openings of yeach of the series102 and 103 arevspaced apart a distance which lmay be either slightly less l(as shown) or slightly greater thafthe `length of an individual 'link of thechain. "Thus, by moving the pins 104: and 105 :into another 'pair'of OPPQSQd openings thejlengthV of .the chain may be adjusted by -an'famount less than vthelength of. a link. Y It lis* also evident that the'fchain 'may be adjusted by an amountequal'toany desired number of .whole links merely by removing vone of lthe'pms andfthen, moving -Vthe fchain to the desired position.

As chains 'constructed as;y abovev described ,may be made-very strong without sacricing strap their 'flexibility to v`any appreciable extent it isv thus -possibleftorbend woo'dnof great tween the laterally spaced members 90a and 90b of the master-strap and which is secured to the bending head by means of ja bolt 166 which enters a threadedopening in` the bending head at a point adjacent'to the pivotal connection of the latter to the link 25. Y

As the operation of the machine is sub- `this 24th day 'of `.lanuary5 stantiallly the saine asl'that" ofthe patented' machine, andas the improved master-strap functions inV the same way as the masterstrap disclosed in thepatent,V itis unecessary to 'describe L the Operation of thegmachine herein.

Y' While a preferred form of chain construction isherein disclosed it is to be under-k stood that other forms of flexible chain may be substituted for that here illustratedwithoutdeparting romthe spiritof the. inven-V tion, while' so l far as its vbroader,aspectsl 'are concerned' it'- Sf Contmnlefed. iihlt thi jchain'jadjusting grneans'than'` those herein vspecifically disclosed 'be's'ubs'tituted` of desired or .that such 'adjustment .maybe dispensedr with under some circumstances."

.Y l claim the chain between' them.'A Y Y .Y

2. A` wood bending machine having a pai-r of bending` heads 'and al liiikfchain'V connecthaving a chamber'for'the reception of the end of the chain,V the head having twfo parallel .series of openings arranged at cf each series being spaced'iapart a distance unequal to the bight of a'chain "link, and removable pins engageablewithy a "selected I 1. A'wod bending machinehavingia pair v lof bending heads and a liexiblechainf cnnecting saidl heads,'oneat leasttlof.saidV heads having` y a channel vfor thejA reception' off the end of the chain, anda plurality of'opeiiings disposedv at opposite sidesI of: the channel,l Y and removable engageablel with thev re-` -spectivecpenings' for clamping a lfink of ,ing'said heads, oneatleast"ofAV the heads Vopposite 'sides of :the chamber, the' openings s,

soA

pair of. said openings to clampithe chain between then. Y H u Y e Signed by meV at Gardner, 'Massachusetts AFRANK VBA Ncnorr.l 

